Peach Blossom Agreement

I thought that a long-lasting friendship would not be destroyed by an agreement. Whether it is a friend or an enemy, friendship can bring not only happiness, but also darkness. They were originally friends, but they turned into enemies. One person is in darkness, and the other person is suffering in light and darkness. Is it all because of friendship? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.